Mairtin O Muilleoir told Stormont it would not be easy to get to the truth behind the Nama controversy

US business figures believe there was "something rotten" in the controversial sale of Nama's assets in Northern Ireland, Stormont's Finance Minister has claimed

Mairtin O Muilleoir told the Assembly while there was concern among would-be investors stateside, he said they were also heartened that the authorities in the US and Ireland were striving to uncover "the truth" surrounding the deal.

Allegations of wrongdoing linked to the £1.2 billion transaction between Nama - the Republic of Ireland's "bad bank" set up to dispose of bailed out lenders' higher risk loans - and US investment giant Cerberus are currently subject to an investigation by the UK's National Criminal Agency (NCA), police in the Republic of Ireland, and the FBI and the Securities and Exchange Commission (SEC) in the US.

The 2014 sale of Nama's 800 Northern Ireland property assets, called Project Eagle, has been dogged by controversy, and claims of inappropriate fixer fee arrangements, since £7 million linked to it was found in an Isle of Man bank account. All parties involved in, or linked to, the transaction have denied wrongdoing.

The Stormont Finance Minister was challenged during question time by UUP Assembly member Sandra Overend on whether he felt the furore had done the region's international reputation damage.

"As I travel, it is my opinion that business people, particularly in North America, look on this deal in two ways," he said.

"They believe, as do most of us in the House, that there was something rotten in how the deal was fixed, formed and brought over the line, as well as in how £7 million ended up in the Isle of Man. Business people who I meet are heartened by the fact that people are revolted by that and determined to get at the truth."

The Sinn Fein minister added: "Those in high positions in corporate boardrooms in North America also welcome the fact that, on the American side, the purchase of Project Eagle by Cerberus is the subject of intense investigation by the FBI and the SEC. They are two almost parallel but separate lines of investigation.

"The people who I meet are confident that the FBI and the SEC have the resources to get to the truth of what happened. I have said this before, and I will say it again, Mrs Overend: it is my opinion that getting to the truth will not be easy, and I really think that we need an all-island investigation.

"However, I have a lot of faith in the agencies - starting at the level of the FBI and the SEC, and then, of course, the NCA and the gardai - bringing to book and to justice those who are guilty of what I believe was wrongdoing."